G&G doesn't have awesome internals. G&G is actually the bottom teir of the non-china-clone guns. Classic Army, Tokyo Marui, ICS (non-clear ones), VFC, ARES.. all have better internals than G&G.
Basically, if you don't mind spending ~$500 on an airsoft gun, and don't have an immediate pressing urge for one, you'd be better off metting up with an Age Verifacation rep, showing them ID to prove you are 18+, and get access to the classifieds here on the forum. You will then have access to far more brands of guns, and full black, full metal ones at that.
Now, if you ABSOLUTLY must have an AEG now, then the G&G ones are decent enough. I happen to think the halfbreeds are overpriced since for another $150 you can get a full black gun of superior quality, but that's just my opinion.
"Someone in a Prius tried to race me at a stop sign the other day. I couldn't believe it. I had him for the first 100 feet or so but I can only walk so fast."